System, apparatus and process for extraction of bitumen from oil sands

ABSTRACT

An extraction system and process for extracting bitumen from a slurry containing bitumen, solids and water. The system comprises a cyclone separation facility for separating the slurry into a solids component stream and a bitumen froth stream with the bitumen froth stream including water and fine solids. The bitumen froth stream is then delivered to a froth concentration facility for separating the bitumen froth stream into a final bitumen enriched froth stream, and a water and fine solids stream. The final bitumen enriched froth stream is suitable for further processing. The system of the present invention is preferably mobile so that the cyclone extraction facility and the froth concentration facility can move with the mine face at an oil sands mining site, however, it is also contemplated that the system can be retrofitted to existing fixed treatment facilities to improve the operational efficiency of such fixed facilities.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.11/595,817, filed Nov. 9, 2006, which claims priority under 35 U.S.C.§119(e) to Canadian Application No. 2526336, filed Nov. 9, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to systems and methods for extractinghydrocarbons from a mixture that includes solids and water. Moreparticularly, the invention relates to a system and method forextracting bitumen from a hydro-transport slurry created to facilitatemovement of bitumen contained in oil sands from a mining site to aprocessing site.

2. Description of the Related Art

Oil sands, also referred to as tar sands or bituminous sands, are acombination of solids (generally mineral components such as clay, siltand sand), water, and bitumen. Although the term “sand” is commonly usedto refer to the mineral components of the mixture, it is well known thatthis term is meant to include various other components such as clay andsilts. Technically speaking, the bitumen is neither oil nor tar, but asemisolid form of oil which will not flow toward producing wells undernormal conditions, making it difficult and expensive to produce. Oilsands are mined to extract the oil-like bitumen which is processedfurther at specialized refineries. Conventional oil is extracted bydrilling traditional wells into the ground whereas oil sand deposits aremined using strip mining techniques or persuaded to flow into producingwells by techniques such as steam assisted gravity drainage (SAGD) orcyclic steam stimulation (CSS) which reduce the bitumen's viscosity withsteam and/or solvents.

Various methods and equipment have been developed over many years formining oil sands and for extracting desired hydrocarbon content from themined solids.

Conventional oil sand extraction processes involve the following steps:

a) Excavation of the oil sand from a mine face as a volume of orematerial. Generally, this is done using conventional strip miningtechniques and equipment.

b) Comminution of the ore material to reduce it to conveyable size forconveying from the mine face.

c) Combining the comminuted material with water to form a slurry.Generally, the slurry is formed with hot water, and, optionally otheradditives.

d) Pumping the slurry to a primary separation facility to separate themineral from the hydrocarbon components. The pumping step is generallyreferred to as a “hydro-transport” process. During the slurry formationand hydro-transport process, large constituents in the ore material arefurther reduced in size, or ablated, and the process of bitumenseparation from the solid mineral components is commenced. These effectsare referred to as “conditioning” of the slurry.

e) Separating the bulk of the hydrocarbon (i.e. bitumen) content fromthe mineral component in one or more “primary separation vessels” (PSV)wherein the bitumen portion is entrained in a froth that is drawn offfrom the surface of the slurry while a significant portion of themineral is removed as a solids or tailings stream.

f) Hydraulic transport of the tailings to a designated tailings disposalsite.

g) Recovery and recycling of clarified water back to the process whenreleased from the tailings slurry within the tailings disposal site.

The above separation and froth concentration steps constitute initialprimary extraction of the oil sands to separate the bitumen from themineral component. The bitumen froth that results after application ofthe above steps is then delivered to secondary treatment steps thatfurther concentrate and upgrade the bitumen to produce a suitable feedfor upgrading to synthetic crude oil or for refining into petroleumproducts.

Various other intervening steps are also known in the primary extractionprocess such as withdrawal of a middlings layer from the PSV and oilrecovery from tailings by cyclones and flotation to further increase theyield of bitumen from the ore material.

As will be known to persons skilled in the art, the large-scale natureof oil sands mining requires processing facilities of an immense size.As such, these facilities are generally fixed in position. For thisreason, transport of the ore material between the variousabove-mentioned steps generally involves the use of trucks, conveyors,or pipelines or various other known equipment. However, as operationscontinue, it will be appreciated that the mine face normally recedesfurther away from the permanent facilities. This, therefore, increasesthe transport distances and time resulting in increased operating andmaintenance costs and environmental impact.

There exists therefore a need to increase the efficiency of at least thetransport and primary extraction processes to reduce operating costs.One suggestion that has been proposed is for having one or more of theexcavating equipment to be mobile so as to follow the receding mineface. An example of this method is taught in Canadian application number2,453,697, wherein the excavating and crushing equipment is made mobileso as to advance along with the mine face. The crushed ore is thendeposited onto a conveyor, which then transports the ore to a separationfacility. This reference also teaches that the conveyor and separationfacility can periodically be relocated to a different site once the mineface advances a sufficient distance. However, such relocation,particularly of the separation facility including large gravityseparation vessels would involve considerable time, expense and lostproduction.

Another problem faced with respect to oil sand mining involves the factthat sand constitutes the primary weight fraction of the mineralcomponent of the mined ore material. Thus, it is desirable to separatethe minerals as soon as possible “upstream” so as to minimize transportcosts. In addition, the transport of mineral components results inconsiderable wear on the transport mechanisms, which further increasesoperating and maintenance costs. As well, long hydro-transport distancescan over condition the oil sand causing bitumen recoveries to decline asthe distances increase. At the same time, separation of the bitumen andmineral components must be done in such a way as to maximize bitumenyield from the ore material.

Thus, there exists a need for an efficient primary extraction process toseparate bitumen from the mineral components, preferably in proximity tothe mine face to reduce transport costs. The present invention seeks toalleviate at least some of the problems associated with the prior art byproviding a novel system and method for extracting the bitumen from ahydro-transport slurry to create an intermediate bitumen froth suitablefor further processing. The system of the present invention ispreferably mobile so that the primary extraction process can move withthe mine face, however, it is also contemplated that the system can beretrofitted to existing fixed primary treatment facilities to improvethe operational efficiency of such fixed facilities.

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided anextraction system for extracting bitumen from a slurry containingbitumen, solids and water comprising a cyclone separation facility forseparating the slurry into a solids component stream and a bitumen frothstream, the bitumen froth stream including bitumen, water and finesolids; and a froth concentration facility for separating the bitumenfroth stream into a final bitumen enriched froth stream, and a water andfine solids stream.

In a further aspect, the present invention provides a concentratorvessel for separating a bitumen froth stream containing bitumen froth,water and fine solids into a final bitumen enriched froth stream and awater and fine solids stream, the concentrator vessel comprising aninlet region to receive the bitumen froth stream and distribute thebitumen froth stream as a substantially balanced flow across aseparation region; the separation region being adapted to establishuniform, substantially horizontal flow of the bitumen froth stream topromote separation of the bitumen froth from the water and fine solids,the bitumen froth tending to move upwardly to accumulate as a frothlayer atop a water layer with the fine solids settling within the waterlayer; and a froth recovery region in communication with the separationregion having an overflow outlet to collect the bitumen froth layer asthe bitumen enriched froth stream, and an underflow outlet to collectthe water and fine solids as the water and fine solids stream; and aflow level control means to control the level of the water layer withinthe vessel to permit the overflow outlet to collect the bitumen frothlayer despite variations in the volume of the bitumen froth stream.

The extraction system of the present invention is preferably mobile sothat the cyclone extraction facility and the froth concentrationfacility can move with the mine face at an oil sands mining site,however, it is also contemplated that the system can be retrofitted toexisting fixed treatment facilities to improve the operationalefficiency of such fixed facilities. In this regard, the cycloneextraction component and the froth concentration component may be mobileas separate units or as a combined unit. In addition, a waterclarification facility can also be incorporated into the extractionsystem for separating the water and fine solids stream from the frothconcentration facility into a water stream and a fine solids stream.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present invention are illustrated, merely by way ofexample, in the accompanying drawings in which:

FIG. 1A is a flow diagram showing a first embodiment of the system ofthe present invention for extracting bitumen from a slurry containingbitumen, solids, and water which makes use of a cyclone separationfacility having a three stage countercurrent cyclone configuration.

FIG. 1B is a flow diagram showing an alternative embodiment of thesystem which employs a cyclone separation facility having two cyclonestages.

FIG. 1C is a flow diagram showing a further alternative embodiment ofthe system which employs a cyclone separation facility having a singlecyclone stage.

FIG. 2 is a schematic view showing a modular, mobile extraction systemaccording to an aspect of the present invention incorporating aplurality of mobile cyclone separation stages forming a mobile cycloneseparation facility and a mobile froth concentrator vessel defining amobile froth concentration facility.

FIG. 3 is a top plan schematic view showing an embodiment of a frothconcentrator vessel.

FIG. 4 is side elevation view of the concentrator vessel of FIG. 3.

FIG. 5 is a top plan schematic view showing an alternative concentratorvessel incorporating a turn in the diverging channel.

FIG. 6 is a perspective view of a concentrator vessel according toanother embodiment.

FIG. 7 is a top plan view of a concentrator vessel according to afurther embodiment.

FIG. 7A is a cross-sectional elevation view taken along line 7A-7A ofFIG. 7.

FIG. 7B is a side elevation view taken along line 7B-7B of FIG. 7.

FIG. 7C is an end view of the concentrator vessel of FIG. 7 showing theoverflow outlet end and the bitumen froth exit nozzle.

FIG. 7D is an opposite end view of the concentrator vessel of FIG. 7showing the underflow outlet end and the water and fine solids exitnozzle.

FIG. 7E is a detail section view taken along line 7E-7E of FIG. 7showing details of a froth recovery weir to collect froth dischargedthrough the underflow outlet.

FIG. 8A-8C are schematic views of an alternative concentrator vesselaccording to a still further embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1A, there is shown a flow diagram of an extractionsystem according to an aspect of the present invention for extractingbitumen from a conditioned oil sand slurry that includes bitumen, solidsand water. This slurry may be created by conventional techniques or byother techniques such as the mobile oil sand excavation and processingsystem and process described in applicant's co-pending Canadian patentapplication no. 2,526,336 filed on Nov. 9, 2005 and entitled METHOD ANDAPPARATUS FOR OIL SANDS ORE MINING. This mobile oil sand excavation andprocessing system is capable of excavating, comminuting or crushing, andslurrifying oil sand ore and moving with the mine face. In a preferredarrangement, the system and process illustrated in FIG. 1A are designedto be mobile for movement with the mine face and the excavation and oreprocessing system, however, the present system can also be retrofittedto existing fixed froth treatment facilities to improve the operationalefficiency of such fixed facilities.

Initially, the system of FIG. 1A includes a cyclone separation facility102, also referred to as a de-sanding or, more accurately, ade-mineralising facility for treatment of incoming slurry 100. Thecyclone separation facility 102 comprises a plurality of cyclones whichaid in de-mineralizing slurry 100. A water feed 104 is also provided tothe cyclone separation facility 102 as a water wash to the slurry flow.The water feed 104 may be from an external water source, recycled waterfrom upstream or downstream processes and/or a mixture of any two ormore of these water sources. The cyclone separation facility 102 servesto efficiently separate a large portion of the solids component from thebitumen component, producing a diluted bitumen froth stream 114 (alsotermed a lean bitumen froth stream), while a large portion of the solidscomponent is separated as a tailings stream 128 from the separationfacility 102.

The solids or mineral component of the incoming slurry 100 is asignificant portion, by weight, of the excavated ore from the mine site.By way of example, incoming slurry 100 can have a composition within thefollowing ranges: about 5-15% bitumen by weight, about 40-70% solids(minerals) by weight and about 30-75% water by weight. In a typicalslurry, the composition will be in the range of about 7-10% bitumen byweight, about 55-60% minerals by weight, and about 35% water by weight.Thus, in order to increase the efficiency of the oil sands strip miningsystem, removal of much of the solids component (minerals excludingbitumen) is preferentially conducted as close to the mine face aspossible. This avoids unnecessary transport of the solids componentthereby avoiding the operation and equipment maintenance costsassociated with such transport.

In some aspects of the present invention, the incoming slurry 100 may beconditioned so that aerated bitumen is liberated from the sand minerals.This stream may be diluted with water and/or overflow from a downstreamcyclone to maintain cyclone feed densities in a preferred range in theorder of 1200-1320 kg/m3. Other cyclone feed densities may apply tospecific operational or installation requirements for processesdescribed herein.

In one embodiment, cyclone separation facility 102 includes threecyclone separation stages 106, 108 and 110 that are connected in seriesand, more preferably, in a counter-current arrangement (as discussedbelow). The cyclone separation stages of each comprise one or morecyclones that are generally vertical units, which have a minimalfootprint, thereby occupying a minimal area. In alternative embodiments,cyclone installation may provide for mounting the cyclones on an angle.This may reduce the height used for installation and/or support and maydirect the underflow streams to a common pumpbox. This may provide forreduced costs associated with the use of launders. This can beparticularly desirable in relation to those embodiments of the presentinvention which are directed to a mobile cyclone separation facility.Suitable cyclones for the cyclone separation stages include any cyclonecapable of separating a significant amount of the solids component froma bitumen based slurry, and include those manufactured by KrebsEngineers (www.krebs.com) under the trademark gMAX®, and thosemanufactured by sold under the name of Cavex cyclones marketed by WeirMinerals (www.weirminerals.com).

The slurry 100 (including the bitumen and solid components of the ore)is fed to the first cyclone separation stage 106 wherein a firstseparation of the bitumen froth and solids is conducted in aconventional manner. Optionally, the slurry 100 is processed by ascreening and/or comminuting unit 105 before entering the first cycloneseparation stage 106 to ensure that solid particles in the slurry can behandled by the cyclone. Rejected solid particles can either be discardedafter screening or made smaller by crushing or other suitabletechniques. An exemplary sizing roller screen for carrying out thescreening and re-sizing process is disclosed in commonly ownedco-pending Canadian Patent application no. 2,476,194 filed Jul. 30, 2004and entitled SIZING ROLLER SCREEN ORE PROCESSING APPARATUS. In the firstcyclone separation stage 106, slurry 100 is processed in a conventionalmanner to produce a first bitumen froth 112, and a first solid tailingsstream 116 which comprises significantly less bitumen and substantiallymore solids than found in the first bitumen froth 112. Bitumen froth 112is delivered to a diluted froth collection stream 114, while first solidtailings stream 116 is pumped to a feed stream 118 of the second cycloneseparation stage 108 where a further cyclone separation process isconducted. The bitumen froth 120 from the second cyclone separationstage 108 is reintroduced to the feed stream 100 supplying the firstseparation stage 106. The tailings stream 122 from the second cycloneseparation stage 108 is combined with the water feed 104 and recycledwater 142 to form a feed 124 to the third cyclone separation stage 110.The bitumen froth 126 from the third stage 110 is combined into the feed118 to the second separation stage 108. The tailings from the thirdstage 110 form a first tailings stream 128, which may be pumped to adisposal site such as a tailings pond 149.

In the embodiment illustrated in FIG. 1A, the three stage cycloneseparation system incorporating a counter-current process and a waterfeed 104 results in a first flow 111 (dash-dot line in FIG. 1A) ofprogressively enriched bitumen froth from the downstream cycloneseparation stage 110 through the intermediate cyclone separation stage108 to the upstream cyclone separation stage 106. At the same time,there is an opposite (counter-current) flow 113 (dotted line in FIG. 1A)of mineral tailings from the upstream stage 106 to the intermediatestage 108, and finally to the downstream stage 110. In such a facility,effectively the hydro-transported ore slurry 100 is mixed with acounter-current wash of water to form bitumen froth stream 114 which isthen drawn off and further processed to extract the desired hydrocarbonsentrained therein. The counter-current water wash of the bitumen flowserves to improve the recovery efficiency of the bitumen. In thissystem, it will be understood that a three-stage process is preferred.However, it will be apparent to persons skilled in the art that eitheran addition or reduction in the number of cyclone stages used in theprocess will also depend upon factors such as the desired recovery ofbitumen, the ease of separation of the bitumen from the mineralcomponent, and economic factors involving the usual trade-off betweenequipment costs and the value of the recovered bitumen product.

In addition, it will be understood that the cyclone separation facilityis more efficient when operated in a water wash manner. The term “waterwash” refers to the manner in which the slurry and water streams aresupplied at opposite ends of a multi-stage process as discussed above.Thus, for example, water entering the process (either make-up orrecycled) is first contacted with a bitumen-lean feed. While wash wateris shown being introduced at the downstream cyclone separation stage110, it will be appreciated that wash water 104, or a portion thereof,can also be introduced at the other cyclone separation stages dependingon the ore grade.

A further advantage of the multi-stage cyclone separation facilityillustrated in FIG. 1A lies in the fact that size of the componentfacility may be reduced since the multi-stage counter-current processresults in a separation efficiency roughly equivalent to a much larger,single PSV stage system. For this reason, embodiments of the multi-stagefacility of the present invention may be mounted on a mobile platform oron movable platforms and, in the result, such facility may be mademoveable along with the oil sands mine face. However, the multi-stagecyclone separation facility may also be configured in a fixedarrangement.

In view of the comments above, the cyclone separation facility 102illustrated in FIG. 1A is preferably an independently moveable facilitywhere one desires to operate the facility as close to the oil sand mineface as possible. In such a case, the only stream requiring majortransport comprises the bitumen froth stream 114 exiting from thecyclone separation facility, with tailings optionally deposited orstored close to the mine face. The cyclone separation facility removesthe bulk of the solids from the ore slurry 100 at or close to the oilsand mining site thereby minimizing the need for transporting suchmaterial and the various costs associated therewith. Movement of thecyclone separation facility 102 may be accomplished by a mobile crawler(such as, for example, those manufactured by Lampson International LLC)or by providing driven tracks on the platform(s) supporting theseparation stages. Various other apparatus or devices will be apparentto persons skilled in the art for achieving the required mobility.

By way of example, FIG. 2 shows a setup according to an aspect of theinvention in which each cyclone separation stage 106, 108 and 110 ismounted on its own independent skid 160 to form a mobile module.Positioned between each cyclone separation stage skid 160 is a separatepump skid 162 which provides appropriate pumping power and lines to movethe froth streams and solid tailings streams between the cycloneseparation stages. It is also possible that any pumping equipment orother ancillary equipment can be accommodated on skid 160 with thecyclone separation stage. In the illustrated arrangement of FIG. 2,groups of three mobile modules are combinable together to form cycloneseparation facilities 102, 102′, 102″ to 102 n as needed. Alsoassociated with each cyclone separation facility is a mobile frothconcentration facility 130 which will be described in more detail below.

Each cyclone separation facility and associated froth concentrationfacility in combination define the smallest effective working unit 200of the extraction system according to the illustrated embodiment. Thismodular arrangement of the extraction system provides for both mobilityof the system and flexibility in efficiently handling of differentvolumes of ore slurry. For example, mobile modules comprising skids orother movable platforms with appropriate cyclone stage or frothconcentration equipment on board may be assembled as needed to createadditional mobile extraction systems 200′, 200″ to 200 n to deal withincreasing ore slurry flows provided by hydro-transport line 101. Oreslurry from the transport line 101 is fed to a manifold 103 whichdistributes the slurry to a series of master control valves 165. Controlvalves 165 control the flow of ore slurry to each mobile extractionsystem 200 to 200 n. This arrangement also permits extraction systems tobe readily taken off-line for maintenance by switching flow temporarilyto other systems.

It will be apparent to persons skilled in the art that otherarrangements of the cyclone separation facility and the frothconcentration facility are possible to enhance the mobility of thecombined system. In an alternative arrangement, the cyclone separationfacility 102, the froth concentration facility 130, and associatedauxiliary equipment for pumping may all be positioned on a common skidsuch that a single skid operates as the smallest effective working unitof the extraction system. Due to the volumes of water re-circulated inthe extraction process, a single skid supporting facilities in closeproximity as an independent working unit can provide significant costadvantages. The skid may also include the water recover unit 140(discussed in more detail below).

The separation efficiency of the multi-stage counter-current cycloneseparation facility allows the extraction system to be used with avariety of ores having different bitumen contents and solids contents.In the case of solids contents, both the mineral components and thefines components including silts and clays can vary. As will bediscussed below, it is possible for the cyclone separation facility tooperate with a single cyclone separation stage or a pair of cycloneseparation stages depending on the ore content, however, the three stagecounter-current arrangement is the preferred arrangement for efficientseparation over the widest range of ore grades.

The system and process contemplated herein are not limited to the threestage countercurrent cyclone separation facility 102 illustrated, by wayof example, in FIG. 1A. The number of cyclone stages in the cycloneseparation facility 102 are primarily influenced by economics includingsuch factors as the trade-off between equipment costs and the value ofthe recovered product.

By way of further example, FIG. 1B shows an alternative embodiment of asystem for extracting bitumen having a cyclone separation facility 102that includes two cyclone separation stages 106 and 108 that areconnected in a counter-current arrangement. The cyclone separationstages each comprise one or more hydrocyclones that are generallyvertical units, which have a minimal footprint, thereby occupying aminimal area. In further alternative embodiments, cyclone installationmay provide for mounting the cyclones on an angle. This may reduce theheight used for installation and/or support and may direct the underflowstreams to a common pumpbox. This may provide for reduced costsassociated with the use of launders. This can be particularly desirablein relation to those embodiments of the present invention which aredirected to a mobile cyclone separation facility.

In the facility of FIG. 1B, the slurry 100 (including the bitumen andsolid components of the ore) is fed to the first cyclone separationstage 106 wherein a first separation of the bitumen froth and solids isconducted as described above. Optionally, the slurry 100 is processed bya screening and/or comminuting unit 105 before entering the firstcyclone separation stage 106 to ensure that solid particles in theslurry can be handled by the cyclone. Rejected solid particles caneither be discarded after screening or made smaller by crushing or othersuitable techniques. In the first cyclone separation stage 106, slurry100 is processed in the manner described above to produce a firstbitumen froth 112, and a first solid tailings stream 116 which comprisessignificantly less bitumen and substantially more solids than found inthe first bitumen froth 112. Bitumen froth 112 is delivered to a frothcollection stream 114, while first solid tailings stream 116 may bediluted with wash water 104 and pumped to a feed stream 118 of thesecond cyclone separation stage 108 where a further cyclone separationprocess is conducted.

The bitumen froth 120 produced by the second cyclone separation stage108 is reintroduced to the feed stream 100 supplying the firstseparation stage 106. The tailings stream 128 from the second cycloneseparation stage 108 may be optionally mixed with fine tailing stream144 and pumped to a disposal site such as a tailing pond 149. Thetailings streams tend to be high density streams that are challenging topump on a sustained basis. The addition of fine tailings stream 144improves the pumpability of tailings stream 128. It will be noted thatmany of the alternative embodiments as described herein with respect tothe illustrated embodiments of FIG. 1A may also be applied to theillustrated embodiments of FIG. 1B.

A system for extracting bitumen that incorporates a cyclone separationfacility 102 that makes use of a single cyclone stage is also possible,and is specifically illustrated in FIG. 1C. In FIG. 1C, the samefeatures as described in previous embodiments are labeled with the samereference number. In this embodiment, the single cyclone stage 106precludes the use of countercurrent flow between different stages. As inpreviously described embodiments, the slurry 100 is processed by ascreening and/or comminuting unit 105 before entering the single cycloneseparation stage 106 as feed 150 to ensure that solid particles in theslurry can be handled by the cyclone. The single cyclone stage producesbitumen froth 112 and solid tailings stream 128 which comprisessignificantly less bitumen and substantially more solids than found inbitumen froth 112. Bitumen froth 112 is delivered to a diluted frothcollection stream 114, while solid tailings stream 128 may be optionallymixed with fine tailing stream 144, and directed to tailings disposalsite 149. The single stage facility still makes use of wash water 104and recycled water 142 to dilute the slurry entering the cyclone stage106.

The diluted bitumen froth stream 114 obtained from the de-mineralizingcyclone separation facility 102 is unique in that it contains a higherwater concentration than normally results in other separationfacilities. In this regard, the present system creates a bitumen frothstream 114 (a bitumen-lean froth stream) that is more dilute thanheretofore known. In known separation facilities, the resulting bitumenenriched stream typically has a bitumen content of about 60% by weight,a solids content of approximately 10% by weight, and a water content ofapproximately 30% by weight. With the system and process according to anaspect of the present invention, however, sufficient water is added aswash water 104 to create a bitumen froth stream 114 having a bitumencontent in the range of about 5-12% by weight, a solids content in therange of about 10-15% by weight and a water content of about 60-95% byweight. It will be understood that when the water content is in thehigher concentrations (above about 85% by weight) the bitumen contentand solids content may be below about 5% and 10% by weight,respectively. It will also be understood that the above concentrationsare provided solely for illustrative purposes in one aspect of thepresent invention, and that in other variations various otherconcentrations will or can be achieved depending on various processparameters.

The present system and process create a diluted bitumen froth stream 114as a result of washing the froth stream with water stream 104 and/orrecycled water 142 in order to improve bitumen recovery. The washingassists in the removal of solids in slurry 100. However, the increasedwater content of bitumen froth stream 114 necessitates that the bitumenfroth stream be further processed in an additional step through a frothconcentration facility 130 in order to remove the wash water. Thisensures that the final bitumen enriched froth stream 136 of the presentsystem is of a composition that can be delivered to a conventional frothtreatment facility (not shown) which operates to increase the bitumenconcentration of the product to make it ready for further processing inan upgrade or refinery facility.

Referring to FIGS. 1, 1B and 1C, the bitumen froth stream 114 producedby the cyclone separation facility 102 is delivered to a frothconcentration facility generally indicated at 130. More specifically,the froth stream 114 is preferably pumped to a froth concentrator vessel132 within the froth concentration facility 130. Froth concentratorvessel 132 may comprise a flotation column, a horizontal decanter, aconventional separation cell, an inclined plate separator (IPS) or othersimilar device or system as will be known to persons skilled in the art.In one preferred embodiment, the froth concentration facility comprisesat least one IPS unit. It will also be appreciated that the frothconcentration facility 130 may comprise any number or combination ofunits. For example, in one embodiment, froth concentration facility 130may comprise a separation cell and a flotation column arranged inseries. In another embodiment, the froth concentration facility maycomprise an IPS in association with a high rate thickener. In additionto the bitumen froth stream 114, an air feed 134 may also be pumped intothe froth concentrator vessel 132 to assist in the froth concentrationprocess. In general, however, sufficient air is entrained in the oreslurry during the hydro-transport process and in the froth stream duringthe cyclone separation step that addition of air is not warranted at thefroth concentration step.

The froth concentrator vessels 132 described above tend to be suited toa froth concentration facility 130 according to an aspect of theinvention that is intended to be fixed in place. This equipment does nottend to lend itself to being mobile when in operation due to its largesize.

Within concentrator vessels 132, the froth is concentrated resulting ina final bitumen enriched froth or product stream 136 that may optionallybe transported to a conventional froth treatment facility (not shown) toincrease the bitumen concentration of the product to make it ready forfurther processing in an upgrader or refinery facility. The frothconcentration facility 130 produces a fine solids stream 138 thatcomprises water and the fine solids (silt and clay) that were notseparated at the cyclone separation facility 102. In one embodiment,chemical additives, injected air or other gases may also by used in thefroth concentration facility 130 to enhance the separation of finesolids from the water.

The bitumen froth stream 114 that leaves the cyclone separation facility102 contains bitumen at a concentration of about 5-12% by weight. Asdescribed above, this is a lean bitumen froth stream with a high watercontent. The froth concentration facility 130 is employed to increasethe bitumen concentration in the final bitumen enriched froth stream 136to about 55% to 72% by weight. When this final product of the extractionsystem is transported to a froth treatment facility (as mentionedabove), the hydrocarbon concentration may be further increased to rangefrom about 95% to 98% by weight. It should be noted that theseconcentrations are recited to exemplify the concentration process andare not meant to limit in any way the scope of any aspects of thepresent invention. It will be appreciated, for example, that thespecific concentrations that can be achieved will depend on variousfactors such as the grade of the ore, the initial bitumen concentration,process conditions (i.e. temperature, flow rate etc.) and others.

In one aspect of the present invention, the froth concentration facility130 is a mobile facility that is used in combination with the mobilecyclone separation facility 102 described above. As shown in FIG. 2, afroth concentration facility 130, 130′, 130″ to 130 n is included ineach mobile extraction systems 200′, 200″ to 200 n, respectively, toprovide the necessary bitumen froth concentration step.

In order to meet the mobility arrangement for the froth concentrationfacility 130, a concentrator vessel specially designed for compactnessmay be used with the above-described extraction system. The preferredconcentrator vessel for operation in a mobile facility is a modifiedversion of a horizontal decanter. The modified design functions toefficiently process the lean bitumen froth stream exiting from thecyclone separation facility 102. The use of cyclone separation stages inthe above described cyclone separation facility 102 allows the majorityof the solids material (i.e. the mineral component) in the slurry to beremoved. Such material is known to result in plugging of a device suchas a horizontal decanter. However, since such material is removed by thecyclone separation facility, use of a horizontal decanter design ispossible in the current system. As well, the horizontal decanter designlends itself well to modification to minimize the footprint of theconcentrator vessel. This results in a preferred concentrator vesselhaving a configuration that is compact and readily movable, andtherefore suited for incorporation into mobile embodiments of thepresent invention as described above and as illustrated schematically inFIG. 2.

Referring to FIGS. 3 to 8C, there are shown various embodiments of afroth concentrator vessel 132. Vessels according to this design havebeen found to reliably handle and process froth streams with a watercontent ranging from about 60-95% by weight, and with the majority ofthe solids content being fine solids with less than about 30% of thesolids being of a particle size above about 44 microns. Such a frothstream composition is an example of a typical froth stream compositionproduced by cyclone separation facility 102 described above. However,the concentrator vessel 132 is not limited to handling froth streamswith the above composition.

The preferred concentrator vessel 132 has a basic structure, however,the dimensions and proportions of the various regions of the vessel canvary. Vessel 132 includes an inlet region to receive and distribute thebitumen froth stream as a substantially balanced flow across aseparation region. The separation region is adapted to establishuniform, substantially horizontal flow of the bitumen froth stream whichserves to promote separation of the bitumen froth from the water andfine solids. The substantially horizontal flow allows the bitumen frothto move generally upwardly due to its lower density to accumulate as afroth layer atop a water layer without vector components due to flowthat work against the upward movement. Similarly, the fine solids settlewithin the water layer due to their higher density. A froth recoveryregion is provided in communication with the separation region with anoverflow outlet to collect the accumulated bitumen froth layer. There isalso an underflow outlet to collect the water and fine solids as acombined material stream or as separate material streams. A flow levelcontrol device, preferably in the form of an overflow weir is used tocontrol the level of the water layer within the vessel to permit theoverflow outlet to collect the bitumen froth layer despite variations inthe volume of the bitumen froth stream.

FIGS. 3 and 4 are a schematic plan view and a side elevation view,respectively, of a concentrator vessel 132 showing the major featuresdiscussed above arranged in an exemplary configuration to permit anunderstanding of the overall operation of the unit. The vessel includesan inlet region 170 to receive the bitumen froth stream 114 from cycloneseparation facility 102. Inlet region 170 communicates with a separationregion 172 where bitumen froth is concentrated by separation from thewater and fine solids of the froth stream 114. In this case, separationregion 172 comprises a diverging channel which serves to establishuniform, substantially horizontal flow of the bitumen froth stream. Thediverging channel also functions to slow the flow of the bitumen frothstream 114. Uniform, substantially horizontal flow and slower flowpromote vertical separation of the bitumen froth from the water and thefine solids due to gravity. As best shown in FIG. 3, the diverging walls173 of the channel result in the velocity of the flow through thechannel slowing due to there being an increasing area (wider channel)for the flow to move through. Arrows 175 a show an initial velocity offlow volume through the channel at a time t1 while arrows 175 b show aslower flow velocity at a later time t2 in a wider portion of thechannel. In other words, the volumetric flow rate Q through the channelstays constant, however, the velocity slows as the area available forflow increases. As flow moves through the channel, gravity and theslowing of the flow causes bitumen froth to accumulate as an upper frothlayer 177 atop a lower water layer 178 with fine solids settling withinthe water layer. This is best shown in the side elevation view of FIG.4. The bitumen froth will tend to coalesce and float on the surface ofwhat is primarily an aqueous flow (about 85-90% water by weight) and anyremaining fine solids (silt and clay) in the stream will tend to settlewithin the water layer. The diverging channel of separation region 172ends in a froth recovery region 179 which is formed with an overflowoutlet 182 to collect the bitumen froth layer as a final bitumen frothstream 136. An underflow outlet 184 collects the water and fine solidsstream 138.

In the illustrated embodiment of FIGS. 3 and 4, overflow outlet 182comprises at least one weir formed across the froth recovery region 179.The weir may be a conventional crested weir or a weir 188 having aJ-shaped cross-section (as best shown in FIG. 4). Overflow outlet 182 isformed as a continuous weir about the perimeter or a portion of theperimeter of the froth recovery region 179. Alternatively, overflowoutlet 182 can comprise a plurality of crested weir or J-weir sectionsin the perimeter wall 181 of the froth recovery region 179. The numberand positioning of the weirs about the perimeter of froth recoveryregion 179 will affect the volumetric flow through the concentratorvessel. Any overflow outlet 182 formed in froth recovery region 179communicates with a froth launder 189. In the embodiment of FIGS. 3 and4, the launder 189 extends downwardly and under the vessel to collectthe weir overflow and deliver the final bitumen enriched froth stream136 to a product nozzle 196. The launder may also extend about theperimeter of the froth recovery region.

A flow level control device in the form of an end weir 185 is providedadjacent the froth recovery region to control the level of the waterlayer 178 within the vessel. In the illustrated embodiment, end weir 185is an overflow weir. Use of end weir 185 controls the level of the waterlayer 178 to permit the overflow outlet 182 to collect the bitumen frothlayer 177 despite variations in the volume of the bitumen froth stream.Downstream of end weir 185, water and a fine solids stream 138 flow toan underflow outlet 198 in the form of an outflow nozzle. Opening 184 inend weir 185 is provided to allow for passage of fine solids past theweir.

The flow level control device may be a pump or a valve arrangement tocontrol the level of water layer 178 within the concentrator vessel,however, an end weir 185 provides for the simplest and most reliablecontrol of the water level. To accommodate a wide range of flows, weir185 is preferably configured as a serpentine weir to increase lengthwithin the vessel.

As best shown in FIG. 4, the floor 186 of at least the separation region172 and the froth recovery region 179 are inclined to promote flowthrough the concentrator vessel and to prevent fine solids fromaccumulating within the vessel.

FIG. 4 also shows a preferred arrangement for inlet region 170. Theinlet region preferably includes conditioning means in the form of anenclosure 190 about an inlet pipe 192 for bitumen froth stream 114. Theenclosure and inlet pipe are provided to promote a uniform velocity flowof the froth stream as the stream enters the separation region.Enclosure 190 and inlet pipe 192 serve to isolate the bitumen frothstream 114 entering the vessel at the inlet region 170 from theseparation region 172 to avoid generation of turbulence in theseparation region. The bitumen froth stream exits enclosure 190 througha baffle plate 194 which assists in the establishment of substantiallyuniform velocity flow within the diverging channel.

FIG. 5 shows schematically in plan view an alternative embodiment of aconcentrator vessel 132 for use with various embodiments of the systemof the present invention. In FIG. 5, features that are common to thevessel of FIGS. 3 and 4 are labeled with the same reference number. Theconcentrator vessel of FIG. 5 differs from the vessel of FIGS. 3 and 4primarily by virtue of the fact that the diverging channel defining theseparation region 172 is formed with at least one turn 201 to increasethe length of the channel and the region available for formation of thefroth layer and settling of the fine solids material. Turn 201 may alsoserve to shorten the overall length dimension 202 of the concentratorvessel 132 to make the vessel more compact and suitable for a mobilerole.

In the concentrator vessel embodiment of FIG. 5, there is an outerperimeter wall 204 and a floor which define a flow volume into whichlean bitumen froth stream 114 is introduced after passing through inletregion 170. Diverging channel 172 is formed by at least one barrierwithin the outer perimeter wall. In the illustrated embodiment, the atleast one barrier comprises a pair of diverging plates 206 that define afirst section of the diverging channel 172 between opposed innersurfaces 208 of the plates, and a second section of the divergingchannel after turn 201 between the outer surfaces 210 of the plates andthe perimeter wall 204 of vessel. Turn 201 is formed between the ends212 of the plates and the outer perimeter wall. In the embodiment ofFIG. 5, the froth recovery region 179 is adjacent the outer perimeterwall of the flow volume. The pair of diverging plates 206 are positionedcentrally adjacent inlet region 170 to form a central diverging channelwhich divides into two channels at turns 201 on opposite sides of theflow volume. At turn 201, flow from the first section of divergingchannel 172 is split into two separate flows with each flow reversingcourse through substantially 180 degrees toward inlet region 170 in thesecond section of the diverging channels. This reversing of the flow ateach turn 201 requires slowing and turning of the flow which providesadditional opportunity for the bitumen froth layer to form on the waterlayer of the flow. End wall section 212 of perimeter wall 204 where theflow reverses tends to create a stagnant zone defining a portion of thefroth recovery region for the present vessel for removal of theaccumulated bitumen froth layer. End wall section 212 is thereforeformed with an overflow outlet in the form of an overflow weir thatempties into launder 189 for collection and recovery of the separatedfroth. Side wall sections 214 of the perimeter wall define additionalfroth recovery regions. One or more additional overflow outlets forbitumen froth into launder 189 may be formed in side wall sections 214.The overflow outlets of the side wall or end wall sections may be thecrest weir or J-weir arrangements previously described in the discussionof FIG. 4 or a combination of both. The use of end wall section 212 andside wall sections 214 to provide overflow outlets for the enrichedbitumen froth provides an opportunity to collect the bitumen enrichedfroth product in stages so that the product is recovered as it isproduced. This minimizes “slip” between the froth layer and theunderlying water layer which is important to avoid bitumen beingentrained back into the water layer. The enriched bitumen frothcollected in launder 189 exits from the launder as final product stream136. An overflow weir 218 is formed at the downstream end of eachchannel of the vessel to control the level of the water layer in thevessel as described above with respect to the embodiment of FIGS. 3 and4. Overflow weirs 218 communicate with an underflow outlet to receivethe water and fine solids stream 138.

The concentrator vessel 132 of FIG. 5 may also include an inclined floorformed in the separation region and the froth recovery region to induceflow from the inlet region to the overflow and underflow outlets. Theinclined floor of the flow chamber provides a path for collection ofrejected water and fine solids and enhances removal of these componentswithout re-entrainment of the bitumen froth layer. The inclined floorsalso permit transport of settling solids through port 184 in overflowweir 218. The combined water and fine solids stream which passesoverflow weir 218 leaves the vessel as stream 138 via an underflowoutlet.

The concentrator vessel 132 of FIG. 5 optionally includes a centralbarrier 220 extending between the pair of diverging barriers 208 to forma pair of diverging channels adjacent the inlet region.

FIGS. 6 to 7E show perspective and orthographic views of furtherembodiments of concentrator vessels constructed according to the designprinciples discussed above.

In each embodiment, inlet region 170 is formed with an enclosure 190 andbaffle plate 194 to prevent turbulent flow created when bitumen frothstream 114 is delivered into the inlet region by inlet pipe 192 fromdisturbing the flow in diverging channel 172. Flow exits the inletregion through baffle plate 194 which tends to assist in establishmentof substantially uniform velocity flow within the diverging channel 172of the separation region. As best shown in FIG. 7A, which is across-sectional view taken along line 7A-7A of FIG. 7, and FIG. 7B,which is a side elevation view taken along line 7B-7B of FIG. 7, thefloor 186 of diverging channel 172 defining the first separation regionbefore turn 201 and the floor 188 of the second separation region afterturn 201 are sloped to promote flow through the concentrator vessel andto ensure that fine solids that settle in the water layer continue to betransported along the sloped floor by gravity towards the underflowoutlets 184. By way of example, floors 186 and 188 may have a slope ofabout 3-3.5%, but other inclines are also possible.

Adjacent perimeter walls 230 is the froth recovery region of theconcentrator vessels. Perimeter walls 230 are formed with overflowoutlets in the form of crested weirs or J weirs to allow the bitumenenriched froth layer collecting atop the water layer to overflow fromthe concentrator vessel into froth launder 189. As best shown in FIG.7B, froth launder 189 is formed with a sloped floor 256 that deliversthe collected bitumen enriched froth to one or more product nozzles 196.FIG. 7C, which is an end view of the concentrator vessel, shows productnozzle 196 at a low point in the launder to ensure efficient collectionof the bitumen enriched froth stream.

As best seen in FIGS. 7 and 7E (which is a section view taken along line7E-7E of FIG. 7), at the opposite end of the concentrator vessel, thewater and fine solids stream exits the concentrator vessel past flowlevel control devices in the form of overflow weirs 185. The water layeroverflows each weir 185 and any fine solids collected on the floor ofthe vessel move past weir 185 through underflow outlets 184. A J-weir187 in communication with froth launder 189 is preferably formed beforeeach weir 185 to collect bitumen froth at the end of the dischargechannel. The rejected water and fine solids stream is collected in adischarge section 258 and discharged through outflow nozzle 198. As bestshown FIG. 7D, which is an end view of the concentrator vessel, thedischarge section is formed with a sloped floor and outflow nozzle 198is at a low point in discharge section. Discharge section 258 mayinclude a removable solids clean out box 259 so that any fine solidsthat accumulate in the discharge section can be periodically removed.

As shown in the embodiment of FIG. 6, the concentrator vessel 132 mayoptionally include flow re-direction means in the form of vanes 250 topromote smooth flow through turns 201 in the diverging channels. Vanes250 are adapted to re-direct the flow through turns 201 to maintainsmooth flow lines and prevent mixing of the. Alternatively, the flowre-direction means may also comprise rounded corners formed in the outerperimeter wall of the flow volume to promote smooth, non-mixing flowthrough turns 201.

The concentrator vessel embodiment of FIG. 7 includes a froth layer flowenhancement means 135 to prevent formation of stagnant regions in thefroth layer. In the illustrated embodiment, the froth layer flowenhancement means takes the form of a rotatable paddle element which isoperated to urge the froth layer into movement in any stagnant zonesthat may develop so as to urge the froth layer toward an overflowoutlet.

In the previous embodiments of the concentrator vessel discussed above,FIGS. 3 and 4 illustrate a “high aspect ratio” vessel in that separatingregion 172 is relatively long in length compared to the vessel width.FIGS. 5, 6 and 7 illustrate a “return flow vessel” in that theseparation region 172 is similar in both length and width.

As a further example of the manner in which the concentrator vessel canbe configured to suit specific layout requirements, FIGS. 8A-8C show analternative vessel which is an example of a “low aspect ratio” vessel inthat the flow stream of the separation region 172 is relatively widecompared to the length. This layout is particularly suited to a mobilebitumen extraction system.

Referring to FIGS. 8A-8C, a “low aspect ratio” froth concentrationvessel 132 comprises an inlet region 170A to receive the bitumen frothstream 114 from the cyclone separation facility 102 via a gravity flowchannel. As illustrated in FIG. 8 a the inlet region 170A connects viasystem of splitters and distribution channels to distribute the bitumenfroth stream 114 equally both in volumetric and composition across thelength of the inlet region 170B. It will be noted that a first hydraulicjump 300, distribution channels 302, a second hydraulic jump 304 and fandistributors 306 illustrated in FIG. 8A are only examples of variousdevices and techniques available to persons skilled in the art fordistributing the bitumen froth feed 114.

The inlet region 170B may incorporate perforated distribution plates tostabilize the incoming bitumen froth 114 into the separation region 172.As illustrated in FIG. 8 b, the separation region 172 may be subdividedby parallel vertical baffles 308 such that the geometry for each flowchannel is the same. The vertical baffles 308 result in channel Reynoldsnumbers of about 175,000 and turbulence intensities in the order of 25%from the mean flow.

In the separation zone 172, aerated bitumen droplets tend to moveupwardly to float on the surface of a water layer 178. The dropletscoalesce into a bitumen froth 177 which overflows by gravity intooverflow outlet 182. The overflow outlet illustrated in FIGS. 8B and 8Care a plurality of J-weirs 188 configured to span the width of the frothconcentration vessel 132. Each segment of the J-weir 188 collectsbitumen froth 177 from a specific portion of the froth concentrationvessel 132 and transfers the bitumen froth 177 into the froth collectionlaunder 310 below the froth concentration vessel 132 as best shown inFIG. 8C. The bitumen froth collected in the froth collection launder 310exists from the froth concentration vessel as final product stream 136.Other locations for the froth collection launder 310 may be applied tospecific layout considerations.

The froth concentrator vessel 132 illustrated in FIG. 8C includes aninclined floor from the inlet region 170B to the underflow outlet region312. The inclined floor slope may be in the range of from about 3 to 7%or in the range of about 3-3.5% in the direction of the flow stream andassists gravity in transferring settling fine solids to be dischargedvia the underflow outlet 184. Located at the low point of the separationregion 172, the underflow outlet 184 is a slotted orifice spanning thewidth of the froth concentration vessel and discharges settled finesolids with a portion of the water into the underflow collection launder314. Other apparatuses such as valves can be applied in lieu of theslotted orifice and/or the underflow outlet 184 can be segregated forsubsequent water treatment operations.

The bulk of the water entering into the underflow region exits the frothconcentration vessel 132 via an overflow weir 185. In order to controlthe water level upstream of the weir within the operational tolerancesfor the J-weir to collect bitumen froth, the overflow weir 185illustrated in FIG. 8B may be a long crested or serpentine weirspecified to limit the water level while permitting significantvariations in the water flow rate due to feed fluctuations in the volumeand composition of bitumen froth feed 114. The overflow weir 185discharges into the underflow collection launder 314 and combines withthe underflow outlet 184 discharge as the water and fine solids stream138 from the froth concentrator vessel 132. Note in this arrangementthat the water and fine solids streams are readily separable forhandling in different downstream processes, if desired.

Referring back to FIG. 1A or 1B, in a further embodiment of the systemof the present invention, the water and fine solids stream 138 producedby froth concentration facility 130 is diverted to an optional waterrecovery facility 140 which separates the fine solids stream 138 into awater stream 142 and a concentrated fine solids stream 144. The finesolids stream 144 is preferably combined with the solids stream 128produced by the cyclone separation facility 102. As shown in FIG. 1A-1C,water stream 142 may be recycled into the water feed 104 that issupplied to the cyclone separation facility 102 to create a blendedwater stream. This serves to reduce the amount of new water required bythe system by recycling and reusing water.

Water recovery facility 140 may include any known equipment 141 forseparating water from solids such as, for example, a thickener or acyclone stage. Preferably, water recovery equipment 141 is specificallydesigned to separate small sized solids particles (silt and clay) sincemuch of the larger sized solid particles have been removed upstream inthe cyclone separation facility 102. The most appropriate equipment forthis step will often be a high gravity hydrocyclone unit. A suitablehydrocyclone for the water separation step is a 50 mm Mozleyhydrocyclone as marketed by Natco. Removal of fine solids from waterstream 142 avoids the accumulation of the such solids within the systemand permits recycling of the water. Water recovery facility 140 ispreferably mobile and may comprise a water recovery unit mounted on itsown independently movable platform 166 (see FIG. 2) or incorporated intothe same movable platform as froth concentration facility 130.

The slurry 100 that is fed to cyclone separation facility 102 isgenerally formed using heated water. In conventional bitumen extractionequipment such as primary separation vessels (PSV), where bubbleattachment and flotation are used for bitumen extraction, temperaturecan affect the efficiency of the extraction process. In embodiments ofthe present invention, the extraction process is not as temperaturesensitive since the cyclone equipment provides solid/liquid separationbased on rotational effects and gravity. Extraction efficiency tends tobe maintained even as temperature drops making the cyclone extractionprocess more amendable to lower temperature extraction. This has energysaving implications at the cyclone separation facility 102 where washwater feed 104 or recycled water stream 140 do not have to be heated tothe same extent as would otherwise be necessary to maintain a higherprocess temperature.

In a further aspect of the present invention, as shown in FIG. 1A-1C,the cyclone separation stage 102 may optionally be provided with a“scalping” unit shown at 146. The scalping unit 146 may comprise, forexample, a pump box or the like which serves to remove any froth formedin the slurry feed 100 during the hydro-transport process. It will beappreciated that removal of such bitumen rich froth further increasesthe recovery efficiency of the three-stage counter-current separationstages. The froth stream 148 generated by the scalping unit 146 iscombined into the froth stream 114 resulting from the cyclone separationfacility 102. The remaining slurry from the scalping unit 146 thencomprises the feed 150 to the cyclone separation facility. Asillustrated in FIG. 1A-1C, if a scalping unit 146 is used, the frothstream 120 from the second cyclone separation stage 108 is feddownstream of the scalping unit 146.

In a further optional embodiment, the ore slurry 100 may be providedwith any number of known additives such as frothing agents and the likeprior to being fed to the cyclone separation stage 102. An example ofsuch additives is provided in U.S. Pat. No. 5,316,664. As mentionedabove, the solids components stream 128 shown in FIG. 1A-1C istransported to a tailings disposal site 149. In a preferred embodiment,the solids stream (which may comprise solely the solids component stream128 from the cyclone facility 102 or a combined solids stream includingthe fine solids stream 144 from the water recovery unit 140) is pumpedto a tailings pond where the solids are allowed to settle therebyallowing the water to be drawn off. In one embodiment, a rheologymodifier or other such additive may be added to the solids stream inorder to enhance settlement of the solids material. An example of suchan additive is described in PCT publication WO/2004/9698 19 to CibaSpecialty Chemicals Water Treatments Limited. The solids stream may bepassed through various known equipment such as belt filters, stackingcyclones and the like prior to deposit into tailings disposal site 149.

Throughout the above discussion, various references have been made topumping, transporting, conveying etc. various materials such asslurries, froth and tailings and others. It will be understood that thevarious equipment and infrastructure such as pumps, conveyor belts,pipelines etc. required by these processes will be known to personsskilled in the art and, therefore, the presence of such elements will beimplied if not otherwise explicitly recited.

Although the present invention has been described in some detail by wayof example for purposes of clarity and understanding, it will beapparent that certain changes and modifications may be practiced withinthe scope of the appended claims.

1. A concentrator vessel for separating a bitumen froth streamcontaining bitumen froth, water and fine solids into a final bitumenenriched froth stream and a water and fine solids stream, theconcentrator vessel comprising: an inlet region to receive the bitumenfroth stream and distribute the bitumen froth stream as a substantiallybalanced flow across a separation region; the separation region beingadapted to establish uniform, substantially horizontal flow of thebitumen froth stream to promote separation of the bitumen froth from thewater and fine solids, the bitumen froth tending to move upwardly toaccumulate as a froth layer atop a water layer with the fine solidssettling within the water layer; a froth recovery region incommunication with the separation region having an overflow outlet tocollect the bitumen froth layer as the bitumen enriched froth stream; anunderflow outlet configured to collect the water and fine solids as thewater and fine solids stream; and a flow level control device configuredto control the level of the water layer within the vessel to permit theoverflow outlet to collect the bitumen froth layer despite variations inthe volume of the bitumen froth stream.
 2. The vessel of claim 1 inwhich the flow level control device comprises a flow control weiradjacent the froth recovery region.
 3. The vessel of claim 2 in whichthe flow level control device is a serpentine weir.
 4. The vessel ofclaim 1 in which the flow level control device is a pump.
 5. The vesselof claim 1 in which the flow level control device is a valve.
 6. Thevessel of claim 1 including conditioning means to promote asubstantially uniform velocity flow of the bitumen froth stream.
 7. Thevessel of claim 6 in which the conditioning means comprises an enclosureto isolate the bitumen froth stream entering the vessel at the inletregion from the separation region to avoid generation of turbulence inthe separation region, the bitumen froth stream exiting the enclosurethrough a perforated member.
 8. The vessel of claim 6 in which theconditioning means comprises a diverging channel.
 9. The vessel of claim6 in which the conditioning means comprises at least one channel fordirecting the flow of the bitumen froth stream.
 10. The vessel of claim6 in which the conditioning means comprises a change in elevation in thevessel adapted to create a hydraulic jump in the bitumen froth stream.11. The vessel of claim 6 in which the conditioning means comprises atleast one channel that includes at least one turn to increase the lengthof the channel.
 12. The vessel of claim 1 in which the inlet region ispositioned above the separation and froth recovery regions.
 13. Thevessel of claim 1 in which the overflow outlet comprises at least oneoutlet weir positioned in the froth recovery region.
 14. The vessel ofclaim 13, in which the at least one outlet weir comprises a channelhaving a J-shaped cross-section.
 15. The vessel of claim 1 in which theoverflow outlet communicates with a froth launder that collects thefinal bitumen froth stream.
 16. The vessel of claim 15 in which thefroth launder extends about the perimeter of the froth recovery region.17. The vessel of claim 1 in which at least the separation region andthe froth recovery region include a sloped floor angled to promote flowfrom the inlet region to the overflow and underflow outlets.
 18. Thevessel of claim 17 in which the sloped floor is inclined at an angle inthe range of 3 to 7%.
 19. The vessel of claim 1 including a fine solidsoutlet for discharging fine solids collected in the vessel.
 20. Thevessel of claim 2 in which the flow control weir is positioned upstreamof the underflow outlet.
 21. The vessel of claim 1 in which theseparation region includes at least one turn to increase the length ofthe separation region.
 22. The vessel of claim 21 in which the inletregion communicates with a flow volume enclosed by an outer perimeterwall and a floor, the separation region being defined by at least onebarrier within the outer perimeter wall, the at least one barrierterminating a distance from the outer perimeter wall to form the atleast one turn in the separation region, and the froth recovery regionbeing adjacent the outer perimeter wall of the flow volume.
 23. Thevessel of claim 22 in which the at least one barrier comprises a pair ofdiverging barriers adjacent the inlet region to form the separationregion as a diverging channel centrally within the flow volume, eachbarrier terminating a distance from the perimeter wall to form the atleast one turn in the channel whereby the diverging channel divides intotwo diverging channels formed at opposite sides of the flow volumebetween each barrier and the outer perimeter wall adjacent the barrier.24. The vessel of claim 23 including a central wall between the pair ofdiverging barriers to form a pair of diverging channels adjacent theinlet region.
 25. The vessel of claim 22 including flow re-directionmeans to promote smooth flow through the at least one turn.
 26. Thevessel of claim 25 in which the flow re-direction means comprise vanesadapted to re-direct the flow through the at least one turn.
 27. Thevessel of claim 25 in which the flow re-direction means comprisesrounded corners formed in the outer perimeter walls of the flow volume.28. The vessel of claim 21 in which the at least one turn is throughsubstantially 180 degrees.
 29. The vessel of claim 1 in which the vesselincludes froth layer flow enhancement means to prevent formation ofstagnant regions in the froth layer.
 30. The vessel of claim 29 in whichthe froth layer flow enhancement means comprises a rotatable paddleelement.
 31. An extraction system for extracting bitumen from a slurrycontaining bitumen, solids and water comprising: a cyclone separationfacility for separating the slurry into a solids component stream and abitumen froth stream, the bitumen froth stream including bitumen froth,water and fine solids; and a froth concentration facility for separatingthe bitumen froth stream into a final bitumen enriched froth stream, anda water and fine solids stream, the froth concentration facilitycomprising the concentrator vessel of claim
 1. 32. The system of claim31 in which the slurry is delivered to the cyclone separation facilityby a hydro-transport pipeline.
 33. The system of claim 31 wherein thecyclone separation facility comprises at least one cyclone separationstage.
 34. The system of claim 33 wherein the cyclone separationfacility comprises at least two cyclone separation stages arranged in acounter-current flow configuration with the slurry being fed to anupstream stage and water being fed to a downstream stage.
 35. The systemof claim 33 in which the cyclone separation facility comprises a mobilecyclone separation facility.
 36. The system of claim 35 in which eachcyclone separation stage of the cyclone separation facility comprises amobile module, the mobile modules being combinable to form the mobilecyclone separation facility.
 37. The system of claim 31 in which thefroth concentration facility further comprises at least one deviceselected from the group consisting of a flotation column, a horizontaldecanter, a separation cell, and an inclined plate separator.
 38. Thesystem of claim 31 wherein the froth concentration facility comprises amobile froth concentration facility.
 39. The system of claim 38 in whichthe system comprises a plurality of concentrator vessels, and eachconcentrator vessel is a mobile module, the mobile modules beingcombinable to form the mobile froth concentration facility.
 40. Thesystem of claim 38 in which the froth concentration facility is movableindependently of the cyclone separation facility.
 41. The system ofclaim 31 wherein the cyclone separation facility and the frothconcentration facility are mobile as a single unit.
 42. The system ofclaim 31 in which the inlet region includes conditioning means topromote a uniform velocity flow of the froth stream as the stream entersthe separation region.
 43. The system of claim 42 in which theconditioning means comprise an enclosure to isolate the bitumen frothstream entering the vessel at the inlet region from the separationregion to minimize turbulence intensities in the separation region, thebitumen froth stream exiting the enclosure through a baffle plate toestablish the uniform velocity flow.
 44. The system of claim 31 in whichthe separation region includes at least one turn to increase the lengthof the separation region.
 45. The system of claim 44 in which the inletregion communicates with a flow volume enclosed by an outer perimeterwall and a floor, the separation region being defined by at least onebarrier within the outer perimeter wall, the at least one barrierterminating a distance from the outer perimeter wall to form the atleast one turn in the separation region, and the froth recovery regionbeing adjacent the outer perimeter wall of the flow volume.
 46. Thesystem of claim 45 in which the at least one barrier comprises a pair ofdiverging barriers adjacent the inlet region to form the separationregion as a diverging channel centrally within the flow volume, eachbarrier terminating a distance from the perimeter wall to form the atleast one turn in the channel whereby the diverging channel divides intotwo diverging channels formed at opposite sides of the flow volumebetween each barrier and the outer perimeter wall adjacent the barrier.47. The system of claim 46 including a central wall between the pair ofdiverging barriers to form a pair of diverging channels adjacent theinlet region.
 48. The system of claim 44 including flow re-directionmeans to promote smooth flow through the at least one turn.
 49. Thesystem of claim 48 in which the flow re-direction means comprise vanesadapted to re-direct the flow through the at least one turn.
 50. Thesystem of claim 48 in which the flow re-direction means comprisesrounded corners formed in the outer perimeter walls of the flow volume.51. The system of claim 44 in which the at least one turn is throughsubstantially 180 degrees.
 52. The system of claim 31 in which theconcentrator vessel includes froth layer flow enhancement means toprevent formation of stagnant regions in the froth layer.
 53. The systemof claim 52 in which the froth layer flow enhancement means comprises arotatable paddle element.
 54. The system of claim 31 in which theoverflow outlet comprises at least one weir formed at a perimeter of thefroth recovery region.
 55. The system of claim 54 in which the at leastone weir comprises a J weir.
 56. The system of claim 54 in which theoverflow outlet communicates with a froth launder that collects thefinal bitumen enriched froth stream.
 57. The system of claim 56 in whichthe froth launder extends about the perimeter of the froth recoveryregion.
 58. The system of claim 31 in which at least the separationregion and the froth recovery region include a floor inclined to createflow from the inlet region to the overflow and underflow outlets. 59.The system of claim 56 including a weir adapted to permit any bitumenfroth that exits the underflow outlet to overflow into the frothlaunder.
 60. The system of claim 31 further comprising a water recoveryfacility for separating the water and fine solids stream from the frothconcentration facility into a water stream and a fine solids stream. 61.The system of claim 60 wherein the water stream from the water recoveryfacility is recycled to the cyclone separation facility.
 62. The systemof claim 61 wherein the water recovery facility comprises at least onewater separation unit selected from the group consisting of a cyclonestage and a thickener.
 63. The system of claim 60 in which the waterrecovery facility is a mobile facility.
 64. The system of claim 31further comprising a scalping unit to remove bitumen rich froth from theslurry prior to entering the cyclone separation facility.
 65. The systemof claim 31 further comprising a screening and comminuting unit toscreen and re-size solids particles from the slurry that exceed apre-determined size prior to entering the cyclone separation facility.